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1. Field of the Invention
The system of the present invention relates to high torque and high capacity rotatable center core and floatable seal body assemblies with universal ram applications and the method of undertaking same. More particularly, the present invention relates to a seal assembly that would allow one to pick up the entire weight of the drill string, tubing or pipe which would allow one to rotate from the top and have the torque completely through it while rotating.
2. General Background of the Invention
In undertaking wireline work utilizing a side entry device, in the present state of the art, the device includes a packoff assembly at the entry to the side entry port which provides for protection against blowouts while the device is in use. However, while wireline is being lowered through the device, there must be an additional method to seal off the passageway while the wireline is in place. Therefore, there are provided blowout preventors positioned above the wireline packoff on the side entry device which may be manually or hydraulically closed to seal off the wireline in case of a blowout. Such blowout preventors are manufactured by, for example, Bowen, and are quite commonly used.
However, it would be beneficial to have such a blowout preventor located in the drill string itself, above the rig floor, which would allow the wireline to be sealed off below the swivel above the rig floor. In that manner, when the drill string below the swivel need to be rotated to provide torque, the blowout preventor would simply rotate with the string. However, in the case of a blowout, or in the event work needed to be done above the swivel in the side entry device, while the well is under pressure, the blowout preventors could be closed off. The type of blowout preventor currently used, as discussed above, manufactured by Bowen, would not have the capability of being placed within the drill string, since the device could not withstand the enormous weight of the drill string below the preventor. So, there is a need for a type of blowout preventor that can be positioned below the swivel, within the drill string, that can be maintained open, and allowed to rotate freely with the string, but in the event of work needed to be done above the device, the blowout preventors would be closed, and the well, although under pressure would not be capable of blowing out during the curative work.
The system of the present invention solves the problem in the art in a simple manner. What would be provided is at least one blowout preventor, positioned within the drill string, above the rig floor, between a swivel and a length of drill pipe below, the apparatus including a principal body portion having a central bore for accommodating a central assembly, having a first under end attached to the lower end of the swivel, and a lower end attached to the drill pipe below; the central assembly would include a central bore for accommodating the passage of fluid or wireline through down hole; there is further provided a pair of transverse bores which would be aligned with the pair of transverse bores in the principal body portion so as to provide a piston within the bores, capable of moving into the central bore of the central assembly to seal the central bore from flow therethrough; there is further provided a sleeve slidably engaged within the transverse bores for aligning the bores of the body and the central assembly; the central assembly would provide an annular shoulder around its lower portion so that the principal body would rest upon when the transverse bores are aligned; there would be provided an upper ring in the wall of the central assembly to maintain the principal body in place between the shoulder and the upper ring; further, there are provided sealing rings to prevent fluid in the pistons of the blowout preventor from seeping into other parts of the assembly. There may be provided a plurality of the blowout preventors stacked one upon the other, which would allow multiple sealing off of the wireline, or other small pipe as wash pipe or coiled tubing but would not be interconnected so as to avoid potential stretching when the central assembly must take the weight of the drill string down hole.
The apparatus and method involved would allow one to pull on a center core and have the block with the rams without exerting any pull on the outside body of the block, which would allow one to rotate the drill string without having the torque on the ram body exerted. By using singles in the system, if the center core would have stretch and torque, the ram body would not be stretched or torqued in the present method.
This system would not only be used for drill pipe but may include the fact that when running wireline, the line may ball up under the pack off or grease head flow tubes. If pressure is exerted on the well, in order to correct the problem, one will close the rams in order to seal off the pressure and bleed off above the rams to correct the wireline problem. If one has a pump down tool below the rams, this would allow one to pump fluids downhole if one would need to kill the well.
Therefore it is a principal object of the present invention to provide a blowout preventor system above the rig floor within the drill string to allow sealing off downhole in order to do work on a side entry or top entry device above the swivel.
It is a further object of the present invention to provide a blowout preventor system in the drill string above the rig floor which can withstand the weight of the drill string without damage to the blowout preventor.
It is a further object of the present invention to provide a blowout preventor system in the drill string above the rig floor which would allow for a plurality of disconnected blowout preventors aligned in sequence to take the weight of the drill string but avoid the preventors from being damaged.
It is a further object of the present invention to include a method and apparatus, which would provide a seal assembly in the drill string that would allow one to pick up the entire weight of the drill string tubing or pipe by being able to rotate from the top and have the torque completely go through it in order to rotate the pipe below it.
It is a further object of the present invention to provide a system which would allow tools or pipe to enter down the center bore of the apparatus, and would allow it to be closed to control well pressure below it so that any tools or pipe above it which would need to be worked or changed could do so while controlling well pressure below it.
It is a further object of the present invention to provide a system for use on chemical cutting or regular logging applications where you can use under high pressure tubing connections or high pressure connections which would include a grease head on top to control well pressure. This would allow one to eliminate the Bowen quick connects which are normally used without elevators and would not have pull on the tubing below.
It is a further object of the present invention to provide a system which is applicable when doing many types of applications, so that one is able to pull while chemical cutting the pipe below with heavy loads and still have the availability to rotate the pipe. The blow out preventors of the present state of the art cannot rotate or withstand heavy loads, as is the present invention.